PEM electrolytic water hydrogen production system hydrogen oxygen concentration safety control and water quality maintenance system

Abstract

The utility model discloses a kind of PEM electrolytic water hydrogen production system hydrogen-oxygen concentration safety control and water quality maintenance system, including PEM electrolytic stack, circulating water tank, water circulation subsystem, hydrogen treatment subsystem connected on the PEM electrolytic stack, oxygen extraction fan, hydrogen concentration sensor, controllable air introduction device, water replenishing system or / and bypass purification module, control system, the utility model realizes in low cost emptying oxygen gas, simultaneously, actively prevents and treats hydrogen accumulation risk, and can quickly repair water quality, solves the contradiction of safety and water quality protection.

Description

Technical Field

[0001] This utility model relates to the technical field of PEM electrolysis for hydrogen production, and in particular to a system for safe control of hydrogen and oxygen concentration and water quality maintenance in a PEM electrolysis system for hydrogen production. Background Technology

[0002] For small and medium-sized PEM water electrolysis hydrogen production equipment, for economic reasons, an oxygen pump is often used to vent the by-product oxygen at low pressure. In this way, the circulating water tank and oxygen pipeline do not need to withstand the same high pressure as the hydrogen side, thus reducing costs.

[0003] However, this operating method has two major risks:

[0004] Hydrogen accumulation risk: Low pressure on the oxygen side may exacerbate hydrogen permeation. Permeated hydrogen accumulates in the gas phase space of the circulating water tank. If it cannot be discharged in time, it may reach the explosion limit (4%–75%), posing an explosion risk upon contact with open flames or static electricity.

[0005] Water contamination risk: To eliminate the above risks, an instinctive approach is to increase the power of the oxygen extraction fan and strengthen exhaust. However, this will increase the negative pressure in the water tank, causing air to be drawn back into the system through weak points in the seal. CO2 in the air dissolves in water to form carbonate ions, and other impurities will also contaminate the ultrapure water, leading to a decrease in water resistivity and poisoning expensive catalysts and proton exchange membranes. Utility Model Content

[0006] The purpose of this invention is to solve the problems in the prior art and to propose a PEM electrolysis water hydrogen production system for safe control of hydrogen and oxygen concentration and water quality maintenance, which can resolve the contradiction between safety and water quality protection under low-pressure oxygen discharge conditions.

[0007] To achieve the above objectives, this utility model proposes a PEM electrolysis water hydrogen production system with safe control of hydrogen and oxygen concentration and water quality maintenance system, including a PEM electrolysis reactor, a circulating water tank for supplying water to the PEM electrolysis reactor, a water circulation subsystem for connecting the PEM electrolysis reactor and the circulating water tank, a hydrogen treatment subsystem connected to the PEM electrolysis reactor, and an oxygen extraction fan. The oxygen outlet of the circulating water tank is connected to the oxygen extraction fan through a pipeline. The system also includes:

[0008] A hydrogen concentration sensor is installed in the gas phase space of the circulating water tank to monitor the hydrogen concentration in real time.

[0009] A controllable air introduction device is connected to the pipeline between the oxygen extraction fan and the circulating water tank, and is used to control the introduction of atmospheric air into the pipeline or to shut off the air introduction.

[0010] A water replenishment system for replenishing pure water to the circulating water tank and / or a bypass purification module for purifying the water in the circulating water tank;

[0011] The control system is electrically connected to the hydrogen concentration sensor, the controllable air introduction device, the oxygen extraction fan, the water replenishment system, and / or the bypass purification module, and is used to collect data from the hydrogen concentration sensor to control the controllable air introduction device and the oxygen extraction fan.

[0012] Preferably, the controllable air introduction device includes a three-way valve, the three-way valve having three connections respectively to the oxygen outlet of the circulating water tank, the oxygen extraction fan, and the atmosphere.

[0013] Preferably, the controllable air introduction device further includes an air filter and a flow regulating valve disposed on the side pipeline connected to the atmosphere on the three-way valve.

[0014] Preferably, the system also includes a pressure sensor located in the gas phase space of the circulating water tank and an online resistivity meter located on the water circulation subsystem, and the control system is communicatively connected to the pressure sensor and the online resistivity meter.

[0015] Preferably, the water replenishment system includes a coarse water tank, a pure water machine connected to the coarse water tank, the pure water machine being connected to the circulating water tank, and the input end of the coarse water tank being connected to a water source.

[0016] Preferably, the bypass purification module includes a bypass purifier, a bypass circulation pipeline for connecting the bypass purifier and the circulating water tank, and a valve body disposed on the bypass circulation pipeline.

[0017] Preferably, the water circulation subsystem includes a water circulation pipeline for connecting the PEM electrolytic reactor and the circulating water tank, and a circulating water pump installed on the water circulation pipeline.

[0018] Preferably, the top of the circulating water tank is provided with at least one safety valve, the pressure relief outlet of which leads to an outdoor safe area.

[0019] The beneficial effects of this utility model on the safe control of hydrogen and oxygen concentration and water quality maintenance system of PEM electrolysis water hydrogen production system:

[0020] Intrinsic safety: Through proactive monitoring and intervention, the risk of explosion from hydrogen accumulation is fundamentally eliminated;

[0021] Optimal water quality protection: By changing the introduction of air from "uncontrollable and continuous leakage" to "controllable, short-term, and safety-oriented operation", the time window for water pollution is greatly shortened, and rapid repair is achieved through subsequent compensation. The overall water quality level is maintained at a level far higher than that of systems with continuous backflow.

[0022] Good economic efficiency: It does not require the oxygen side to be designed with the same high pressure level as the hydrogen side, saving costs. At the same time, intelligent control avoids greater economic losses caused by equipment damage.

[0023] High degree of automation: The entire process is completed automatically by the control system without human intervention, ensuring safety and reliability.

[0024] The features and advantages of this utility model will be described in detail through embodiments and accompanying drawings. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of a PEM electrolysis water hydrogen production system for safe control of hydrogen and oxygen concentration and water quality maintenance.

[0026] Figure 2 This is a schematic diagram of the structure of a PEM electrolysis water hydrogen production system after removing the hydrogen treatment subsystem, which is a safe control system for hydrogen and oxygen concentration and a water quality maintenance system.

[0027] In the diagram: 1-PEM electrolytic reactor, 2-circulating water tank, 3-hydrogen treatment subsystem, 4-water circulation subsystem, 5-oxygen extraction fan, 6-controllable air introduction device, 7-three-way valve, 8-hydrogen concentration sensor, 9-pressure sensor, 10-control system, 11-crude water tank, 12-pure water machine, 41-circulating water pump, 42-online resistivity meter, 43-bypass purifier, 61-air filter, 62-flow regulating valve. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. However, it should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit its scope. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the present utility model.

[0029] In the description of this utility model, it should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to or indirectly connected to the other element.

[0030] In the description of this utility model, it should be noted that the terms "center," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "multiple" means two or more, unless otherwise explicitly specified. "Several" means one or more, unless otherwise explicitly specified.

[0031] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0032] Example 1:

[0033] See Figure 1 , Figure 2This utility model discloses a PEM electrolysis water hydrogen production system for safe control of hydrogen and oxygen concentration and water quality maintenance. The system includes a PEM electrolysis reactor 1 for hydrogen production via water electrolysis, a circulating water tank 2 for supplying water to the PEM electrolysis reactor 1, a water circulation subsystem 4 connecting the PEM electrolysis reactor 1 and the circulating water tank 2, a hydrogen treatment subsystem 3 connected to the PEM electrolysis reactor 1, and an oxygen extraction fan 5. The oxygen outlet of the circulating water tank 2 is connected to the oxygen extraction fan 5 via a pipeline. A hydrogen concentration sensor 8 is added to the gas phase space of the circulating water tank 2, and a controllable air introduction device 6 is added to the pipeline before the inlet of the oxygen extraction fan 5 for controlling... The control system 10, which introduces air from the atmosphere into the pipeline or shuts off the air supply, is electrically connected to the hydrogen concentration sensor 8, the controllable air supply device 6, and the oxygen extraction fan 5. It collects data from the hydrogen concentration sensor 8 to control the controllable air supply device 6 and the oxygen extraction fan 5. Specifically, the controllable air supply device 6 includes a three-way valve 7. The first port of the three-way valve 7 is connected to the oxygen outlet pipeline of the circulating water tank 2, the second port is connected to the inlet of the oxygen extraction fan 5, and the third port is connected to the atmosphere. An air filter 61 and a flow regulating valve 62 are installed on the pipeline at the third port. The air filter 61 removes particulate matter. The control system is configured as follows:

[0034] Receive monitoring data from the hydrogen concentration sensor 8;

[0035] When the detected hydrogen concentration exceeds the first preset safety threshold, it is determined to be a risk of hydrogen accumulation; immediately start the safety purging mode: control the controllable air introduction device 6 to open, thereby introducing air from the atmosphere into the input pipe of the oxygen pump 5, and increasing the power of the oxygen pump 5 to introduce a certain amount of external air into the pipe. The oxygen pump 5 purges the gas phase space of the circulating water tank 2 to force dilution and forcibly reduce the hydrogen concentration to a safe range.

[0036] When the detected hydrogen concentration is lower than the second preset safety threshold, exit the safety purging mode;

[0037] The water quality restoration process is then initiated. The circulating water is enhanced through either a water replenishment system or a bypass purification module, rapidly reducing the increased ion concentration caused by air introduction and restoring water quality. This invention achieves low-cost oxygen removal while proactively preventing hydrogen accumulation and quickly restoring water quality, resolving the conflict between safety and water quality protection.

[0038] Specifically, in this embodiment, the first preset safety threshold is 1% (approximately 25% of the lower explosive limit), and the second preset safety threshold is 0.5%.

[0039] Specifically, the enhanced water replenishment is accomplished through a water replenishment system connected to the circulating water tank 2. This system includes a coarse water tank 11 and a pure water machine 12 connected to the coarse water tank 11. The pure water machine 12 is connected to the circulating water tank 2, and the input end of the coarse water tank 11 is connected to a water source. The water replenishment system increases the amount of ultrapure water replenished, thus diluting the circulating water.

[0040] Regarding the bypass purification module, the bypass purification module includes a bypass purifier 43, a bypass circulation pipeline for connecting the bypass purifier 43 and the circulating water tank 2, and a valve body located on the bypass circulation pipeline. Activating the bypass purification module in the water circulation loop 4 can enhance the purification of the circulating water.

[0041] Regarding the structure of the water circulation subsystem 4, the water circulation subsystem 4 includes a water circulation pipeline for connecting the PEM electrolytic reactor 1 and the circulating water tank 2, and a circulating water pump 41 installed on the water circulation pipeline. The circulating water pump 41 realizes the water circulation between the PEM electrolytic reactor 1 and the circulating water tank 2.

[0042] Example 2:

[0043] See Figure 2 Based on Embodiment 1, the system further includes a pressure sensor 9 located in the gas phase space of the circulating water tank 2 and an online resistivity meter 42 located on the water circulation subsystem 4. The control system 10 is communicatively connected to the pressure sensor 9 and the online resistivity meter 42. The control system 10 is configured to: in the safe purging mode, adjust the flow regulating valve 62 and the power of the oxygen pump 5 in real time based on the feedback from the pressure sensor 9 to control the air intake and purging intensity; during the water quality recovery process, determine whether the water quality has recovered to the qualified range based on the reading of the online resistivity meter 42. In this embodiment, the qualified range is below 1 μs·cm.

[0044] To improve safety, a safety valve is installed at the top of the circulating water tank 2, with its pressure relief outlet leading to a safe outdoor area.

[0045] The working process of this utility model:

[0046] This utility model discloses a PEM electrolysis water hydrogen production system for hydrogen concentration safety control and water quality maintenance. During operation, the control system 10 monitors the hydrogen concentration in the circulating water tank 2 by receiving data from the hydrogen concentration sensor 8. When the monitored hydrogen concentration exceeds a first preset safety threshold, it is determined to be a risk of hydrogen accumulation. The system immediately activates the safety purging mode: the controllable air introduction device 6 is turned on, thereby introducing air from the atmosphere into the input pipeline of the oxygen extraction fan 5 and increasing the power of the oxygen extraction fan 5 to introduce a certain amount of external air into the pipeline. The oxygen extraction fan 5 purges the gas phase space of the circulating water tank 2 to forcibly dilute the hydrogen concentration to a safe range.

[0047] When the detected hydrogen concentration is lower than the second preset safety threshold, exit the safety purging mode;

[0048] The water quality restoration procedure is then initiated. This involves either strengthening the water supply through the replenishment system or activating the bypass purification module to enhance the purification of the circulating water, rapidly reducing the increased ion concentration caused by air introduction and restoring water quality.

[0049] All standard parts used in this application can be purchased from the market. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the existing technology. The internal components of the electric slide rail, cylinder, welding machine, electric telescopic rod and controller all adopt conventional models in the existing technology, and their internal structure belongs to the existing technology structure. Workers can complete the normal operation of them according to the existing technical manual. In addition, the circuit connection adopts the conventional connection method in the existing technology, and will not be described in detail here.

[0050] It should be noted that although the above embodiments have been described herein, this does not limit the scope of patent protection for this utility model. Therefore, any changes and modifications made to the embodiments described herein based on the innovative concept of this utility model, or equivalent structural or procedural transformations made using the content of this utility model's specification and drawings, directly or indirectly applying the above technical solutions to other related technical fields, are all included within the scope of protection of this utility model patent.

Claims

1. A PEM electrolysis water hydrogen production system hydrogen-oxygen concentration safety control and water quality maintenance system, comprising a PEM electrolysis stack (1), a circulating water tank (2) for supplying water to the PEM electrolysis stack (1), a water circulation subsystem (4) for connecting the PEM electrolysis stack (1) and the circulating water tank (2), a hydrogen treatment subsystem (3) connected to the PEM electrolysis stack (1), and an oxygen extraction fan (5), the oxygen outlet of the circulating water tank (2) being connected to the oxygen extraction fan (5) through a pipeline, characterized in that It also includes: a hydrogen concentration sensor (8), which is installed in the gas phase space of the circulating water tank (2) for real-time monitoring of hydrogen concentration; a controllable air introduction device (6), which is connected to the pipeline between the oxygen pump (5) and the circulating water tank (2) for controlling the introduction of air from the atmosphere into the pipeline or shutting off the air introduction; a water replenishment system for replenishing pure water to the circulating water tank (2) and / or a bypass purification module for purifying the water in the circulating water tank (2); The control system (10) is electrically connected to the hydrogen concentration sensor (8), the controllable air introduction device (6), the oxygen pump (5), the water replenishment system and / or the bypass purification module, and is used to collect data from the hydrogen concentration sensor (8) to control the controllable air introduction device (6) and the oxygen pump (5).

2. The PEM water electrolysis hydrogen production system hydrogen and oxygen concentration safety control and water quality maintenance system of claim 1, wherein: The controllable air introduction device (6) includes a three-way valve (7), which is connected to the oxygen outlet of the circulating water tank (2), the oxygen pump (5), and the atmosphere in three separate ways.

3. The PEM water electrolysis hydrogen production system hydrogen and oxygen concentration safety control and water quality maintenance system of claim 2, wherein: The controllable air inlet device (6) also includes an air filter (61) and a flow regulating valve (62) installed on the three-way valve (7) for communicating with the atmosphere.

4. The PEM water electrolysis hydrogen production system hydrogen and oxygen concentration safety control and water quality maintenance system of claim 1, wherein: It also includes a pressure sensor (9) located in the gas phase space of the circulating water tank (2) and an online resistivity meter (42) located on the water circulation subsystem (4). The control system (10) is communicatively connected to the pressure sensor (9) and the online resistivity meter (42).

5. The PEM water electrolysis hydrogen production system hydrogen and oxygen concentration safety control and water quality maintenance system of claim 1, wherein: The water replenishment system includes a coarse water tank (11) and a pure water machine (12) connected to the coarse water tank (11). The pure water machine (12) is connected to the circulating water tank (2), and the input end of the coarse water tank (11) is connected to a water source.

6. The PEM water electrolysis hydrogen production system hydrogen and oxygen concentration safety control and water quality maintenance system of claim 1, wherein: The bypass purification module includes a bypass purifier (43), a bypass circulation pipeline for connecting the bypass purifier (43) and the circulating water tank (2), and a valve body provided on the bypass circulation pipeline.

7. The PEM water electrolysis hydrogen production system hydrogen and oxygen concentration safety control and water quality maintenance system of claim 1, wherein: The water circulation subsystem (4) includes a water circulation pipeline for connecting the PEM electrolytic reactor (1) and the circulating water tank (2) and a circulating water pump (41) installed on the water circulation pipeline.

8. The PEM water electrolysis hydrogen production system hydrogen and oxygen concentration safety control and water quality maintenance system of claim 1, wherein: The top of the circulating water tank (2) is equipped with at least one safety valve, whose pressure relief outlet leads to an outdoor safe area.

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